The invention relates to a conjugate which includes a photosensitizer and a targeting moiety, and methods of using the conjugate.
Infectious diseases remain an unsolved problem, due largely to emergence of multiply-antibiotic resistant strains of bacteria, newly discovered viral diseases, and the spread of fungal and protozoan diseases.
Advanced periodontal disease is one of a large number of oral infectious diseases, and is the principal cause of tooth loss in those over 30 years old. Periodontal diseases arise from the interaction between bacterial cells and their products in dental plaque, and the host defense mechanisms (Antczak-Bouckoms, A., (1994), J. Dent. Educ. 58:625-640). Current treatments often rely on mechanical removal of the plaque and bacteria, which can be inefficient (Unsal E. et al., (1995), J. Periodontol. 66:47-51), or antibiotic therapy, which can lead to bacterial resistance (Olsvik, B. et al., (1995), J. Clin. Periodontol. 22:391-396).
Photodynamic therapy (PDT) has been proposed as an attractive method of eliminating oral bacteria and bacteria in topical and gastrointestinal infections because these sites are relatively accessible to illumination. For example, fiber optics can be used to deliver light into the dental pocket (Wilson, M., (1993), J. Appl. Bacteriol. 75:299-306).
The inventor has discovered that classes of molecules not hither to used as targeting moieties for photosensitizers, can be used to target photosensitizers.
Accordingly, the invention features, a conjugate molecule which includes a photosensitizer coupled to a non-pair member (NPM) moiety, e.g., an NPM-polypeptide.
In embodiments in which the targeting moiety includes a polypeptide, the targeting moiety can be a linear, branched, or cyclic polypeptide.
In preferred embodiments, the targeting moiety includes a small anti-microbial peptide (SAMP). Histatins, defensins, cecropins, magainins, Gram positive bacteriocins, and peptide antibiotics can be SAMP""s. In preferred embodiments, the targeting moiety includes a bacterial, fungal, animal, e.g., mammalian, e.g., human, SAMP, or an active fragment or analog thereof.
In preferred embodiments the targeting moiety includes a defensin, or an active fragment or analog thereof. By way of example the defensin can be: a human defensin, e.g., HNP-1, -2, -3, or -4; a guinea pig defensin, e.g., GPNP; a rabbit defensin, e.g., rabbit NP-1, -2, -3A, -3B, or 5; a rat defensin, e.g., rat NP-1, -2, -3, or -4; murine cryptin; bovine granulocyte bactenecin or indolicidin; or bovine seminal plasmin.
In preferred embodiments, the targeting moiety includes a SAMP of insect origin, or an active fragment or analog thereof, e.g., a cecropin from Cecropia moths, bumble bees, fruit flies, or other insects, an apidaecin from honeybees, or an adropin from fruit flies.
In preferred embodiments, the targeting moiety includes a SAMP of amphibial origin, or an active fragment or analog thereof, e.g., a magainin, a PGLA, a XPF, a LPF, a CPG, a PGQ, a bombinin, a bombinin-like peptide BLP-1, -2, -3, or -4, or a brevinin.
In preferred embodiments the targeting moiety includes a SAMP from an invertebrate, or an active fragment, or analog thereof, e.g., tachyplesin I, II, or III, or polyphemusin I or II, from horseshoe crab. In preferred embodiments, the targeting moiety is from a fish, e.g., pardaxin.
In preferred embodiments, the targeting moiety includes a bacteriocin, more preferably a Gram positive bacteriocin, or an active fragment, or analog thereof, e.g., a nisin, a subtilin, epidermin, gallidermin, salivarin, or a lacticin.
In preferred embodiments, the targeting moiety includes a peptide antibiotic, or an active fragment or analog thereof, e.g., a tyrocidin, or a bacitracin.
In preferred embodiments the targeting moiety includes a histatin, or an active fragment or analog thereof, e.g., histatin-1 through -8, preferably histatin-1, -3, or -5. In preferred embodiments the targeting moiety includes histatin-5 residues 13-24, or corresponding residues from other histatins. In preferred embodiments the targeting moiety includes a histatin molecule which has been engineered to include an internal duplication.
In preferred embodiments, the targeting moiety includes a polypeptide having an affinity for a polysaccharide target, e.g., a lectin. By way of example the lectin can be a seed, bean, root, bark, seaweed, fungal, bacteria, or invertebrate lectin. In preferred embodiments, the targeting moiety includes a plant polypeptide, e.g., a lectin from jack bean, e.g., concanavalin A, or a lectin from a lentil, Lens culinaris. 
In preferred embodiments, the targeting moiety includes a salivary polypeptide, or an active fragment or analog thereof. Examples of salivary polypeptides are the histatins, e.g., histatin-1 through -8, or more preferably, histatin-1, -3, or -5. In preferred embodiments the targeting moiety includes histatin-5 residues 13-24, or corresponding residues from other histatins. In preferred embodiments the targeting moiety includes a histatin molecule which has been engineered to include an internal duplication.
In preferred embodiments, the targeting moiety includes a Gram negative bacteriocin, e.g., colicin B, colicin E1, or colicin Ia.
In preferred embodiments the targeting moiety includes bacterially elaborated polypeptide, e.g., nisin, subtilin, epidermin, gallidermin, salivarin, or lacticin.
In preferred embodiments the targeting moiety includes a molecule, e.g., a peptide, other than an antibody or either member of a receptor-ligand pair.
In preferred embodiments, the conjugate does not include, e.g., it is not coupled, e.g., covalently or non-covalently coupled to: a PM; an antibody; an enzyme; a hormone; a receptor on a cell surface; or the ligand for a receptor on a cell surface.
In preferred embodiments the targeting moiety includes a peptide in which at least 10, 20, 30, 40, 50, 60, 70, 80, 90% of the amino acid residues are of one amino acid residue, e.g., a positively charged amino acid residue, e.g., a lysine reside, an arginine residue, or an ornithine residue. Particularly preferred targeting moieties are polyamino acids, e.g., polylysine, polyarginine, or polyornithine.
In preferred embodiments the targeting moiety: is cationic; has a net positive charge of +1, +2 or +3 per molecule; has a net positive charge equal to or greater than +4; includes a positively charged amino acid residue, e.g, lysine; includes at least 2, 3, 4, or more positively charged amino acid residues, e.g, a lysine, arginine, or ornithine residue.
In other embodiments the targeting moiety: is anionic; has a net negative charge of -1, -2 or -3 per molecule; has a net negative charge equal to or greater than -4; includes a negatively charged amino acid residue, e.g, aspartic acid or glutamic acid; includes at least 2, 3, 4, or more negatively charged amino acid residues, e.g, glutamic; includes at least 10, 20, 30, 40, or 50% or more negatively charged amino acid residues, e.g. aspartic acid, or glutamic acid.
In preferred embodiments the targeting moiety: is approximately neutral in charge; includes at least 50, 60, 70, 80, or 90% amino acid residues which are neutral amino acid residues, such as serine, threonine, alanine, methionine, cysteine, or valine.
In preferred embodiments the targeting moiety has a molecular weight of more than 1200, 1800, 2400, 3000, 6000, 10,000, 25,000, 50,000, 100,000, or 200,000 daltons. In preferred embodiments the targeting moiety has a molecular weight of less than 250,000, 150,000, 60,000, 25,000, 10,000, 8,000, or 6,000 daltons. In particularly preferred embodiments the molecular weight of the targeting moiety is between 300 and 1800, 600 and 2400, 1200 and 6,000, 5,000 and 8,000, 8,000 and 15,000, 15,000 and 30,000, 35,000 and 70,000, 70,000 and 150,000, or 150,000 and 300,000 daltons.
In preferred embodiments the targeting moiety includes a peptide at least 3, 6, 12, 18, 24, 30, 60, 100, 250, 500, 1,000, or 2,500 residues in length. In preferred embodiments the targeting moiety is a peptide less than 3,000, 1,500, 700, 300, 150, 100, 80, 60,40, 30, or 15 residues in length. In particularly preferred embodiments the targeting moiety includes a peptide of between 6 and 15, 12 and 18, 18 and 30, 20 and 40, 30 and 60, 80 and 120, 150 and 300, 300 and 600, 800 and 1,200, or 2,000 and 3,000 residues in length.
In preferred embodiments the targeting moiety includes a protein which forms a pore in the permeability barrier of the target organism, e.g., in Staphylococcus aureus, Klebsiella pneumoniae, Candida albicans, Leishmania donovani, or Giardia lamblia. 
In other preferred embodiments, the targeting moiety includes a low density lipoprotein, a high density lipoprotein or a very low density lipoprotein.
In preferred embodiments, the targeting moiety has been selected using a surface molecule of the target organism as an affinity selection or screen, e,g, the targeting moiety has been selected in a chemical or phage display library.
In particularly preferred embodiments the targeting moiety includes a polylysine molecule. The polylysine can be between 6 and 15, 12 and 18, 18 and 30, 20 and 40, 30 and 60, 80 and 120, 150 and 300, 300 and 600, 800 and 1,200, or 2,000 and 3,000 residues in length.
In preferred embodiments the targeting moiety includes a polypeptide, e.g., a polyamino acid, which has been chemically modified to alter its charge, e.g., the charge of side chains of one or more amino acid residues of the polyamino acid. For example, one or more, or approximately 10, 25, 50, 75, 90 or 100% of the charged side chains can be modified. By modified is meant that a negative side chain, e.g., a glutamic acid, or an aspartic acid, side chain is made positive or neutral in charge, a positively charged side chain, e.g., the side chain of lysine, arginine, or ornithine is made negative or neutral in charge. By way of example, one or more of the side chains of polylysine can be made neutral or negative in charge.
In preferred embodiments: the photosensitizer produces singlet oxygen upon absorption of electromagnetic irradiation at the proper energy level and wavelength; the photosensitizer includes a porphyrin or porphyrin derivative; the photosensitizer includes chlorin e6 or a chlorin derivative.
In preferred embodiments the conjugate further includes a backbone member. In such embodiments the backbone is coupled both to a photosensitizer and to a targeting moiety. The backbone can itself also be a targeting moiety, e.g. polylysine.
In preferred embodiments, the conjugate molecule has affinity for a target organism. The target organism, by way of example, can be: a microorganism, e.g., a bacterial cell, a fungal cell, a protozoan cell, a cell of Pneumocystis carinii; a virus; or, a parasitic helminth; or an arthropod.
In preferred embodiments where the cell is a bacterial cell, the bacterial cell can be a Staphylococcus, Streptococcus, Enterococcus, Mycobacterium, Pseudomonas, Salmonella, Shigella, Escherichia, Erwinia, Klebsiella, Borrelia, Treponema, Campylobacter, Helicobacter, Bordetella, Neisseria, Legionella, Leptospira, Serpulina, Mycoplasma, Bacteroides, Klebsiella, Yersinia, Chlamydia, Vibrio, Actinobacillus, Porphyria, Hemophilus, Pasteurella, Peptostreptococcus, Listeria, Propionibacterium, Mycobacterium, Corynebacterium or Dermatophilus cell.
In preferred embodiments where the cell is a fungal cell, the cell can be a Candida or an Aspergillus cell.
In preferred embodiments, the organism is Pneumocystis carinii. 
In preferred embodiments where the target organism is a protozoan cell, the cell is an Entamoeba, a Toxoplasma, a Giardia, a Leishmania, a Crytosporidium, or a Schistosoma.
In preferred embodiments where the target organism is a virus, the virus is an HIV, an HTLV, a hepatitis virus, an influenza virus, a rhinovirus, a papilloma virus, a measles virus, a Herpes virus, a rotavirus, a parvovirus, a psittacosis virus, or an Ebola virus.
In preferred embodiments where the target organism is an arthropod, the arthropod is a parasitic mite.
In preferred embodiments where the target organism is a helminth, the helminth is a nematode or a trematode.
In preferred embodiments the target organism is an oral bacterial species, e.g., Porphyromonas (Bacteroides) gingivalis. 
In another aspect, the invention features a conjugate molecule which includes a photosensitizer coupled to a non-pair member (NPM) targeting moiety and a pharmaceutically acceptable carrier.
In another aspect, the invention features, a conjugate molecule which includes a photosensitizer coupled to a targeting moiety which includes a non-pair member (NPM) polypeptide moiety having affinity for an oral bacterial species.
In embodiments in which the targeting moiety includes a polypeptide, the targeting moiety can be a linear, branched, or cyclic polypeptide.
In particularly preferred embodiments the targeting moiety includes a polylysine molecule. The polylysine can be between 6 and 15, 12 and 18, 18 and 30, 20 and 40, 30 and 60, 80 and 120, 150 and 300, 300 and 600, 800 and 1,200, or 2,000 and 3,000 residues in length.
In preferred embodiments the targeting moiety includes a polypeptide, e.g., a polyamino acid, which has been chemically modified to alter its charge, e.g., the charge of side chains of one or more amino acid residues of the polyamino acid. For example, one or more, or approximately 10, 25, 50, 75, 90 or 100% of the charged side cains can be modified. By modified is meant that a negative side chain, e.g., a glutamic acid, or an aspartic acid, side chain is made positive or neutral in charge, a positively charged side chain, e.g., the side chain of lysine, arginine, or ornithine is made negative or neutral in charge. By way of example, one or more of the side chains of polylysine can be made neutral or negative in charge.
In preferred embodiments: the photosensitizer produces singlet oxygen upon absorption of electromagnetic irradiation at the proper energy level and wavelength; the photosensitizer includes a porphyrin or porphyrin derivative; the photosensitizer includes chlorin e6 or a chlorin derivative.
In preferred embodiments the conjugate further includes a backbone member. In such embodiments the backbone is coupled both to a photosensitizer and to a targeting moiety. The backbone can itself also be a targeting moiety, e.g. polylysine.
In preferred embodiments the conjugate includes chlorin e6 conjugated to polylysine, e.g., 1 or 2 to 20 chlorin e6 molecules conjugated to a polylysine between about 1,000 and 3,000 in molecular weight.
In preferred embodiments the conjugate includes chlorin e6 conjugated to a histatin polypeptide, or an active fragment or analog thereof, e.g., 1 or 2 to 4 chlorin e6 molecules conjugated to a histatin-5 polypeptide.
In preferred embodiments the conjugate includes chlorin e6 and a histatin polypeptide, or an active fragment or analog thereof, conjugated to a polylysine backbone, e.g., either from one to 4 polylysine chains (MW 1,000 to 3,000 daltons, each containing from 1 or 2 to 20 chlorin e6 molecules) joined to one histatin-5 polypeptide, or from one to 4 histatin-5 polypeptides joined to a polylysine chain (MW 1,000 to 3,000 and containing 1 or 2 to 16 chlorin e6 molecules.
In preferred embodiments the target organism is an oral bacterial species, e.g., Porphyromonas (Bacteroides) gingivalis. 
In preferred embodiments, the conjugate does not include, e.g., it is not coupled, e.g., covalently or non-covalently coupled to: a PM; an antibody; an enzyme; a hormone; a receptor on a cell surface; or the ligand for a receptor on a cell surface.
In preferred embodiments, the targeting moiety includes a salivary polypeptide, or an active fragment or analog thereof. Examples of salivary polypeptides are the histatins, e.g., histatin-1 through -8, or more preferably, histatin-1, -3, or -5. In preferred embodiments the targeting moiety includes histatin-5 residues 13-24, or corresponding residues from other histatins. In preferred embodiments the targeting moiety includes a histatin molecule which has been engineered to include an internal duplication.
In another aspect, the invention features, a method of treating a subject, for a disorder characterized by the presence of an unwanted organism. The method includes:
administering to the subject, a conjugate which includes a photosensitizer coupled to a NPM targeting moiety, e.g., a conjugate described herein;
irradiating the subject with energy of a wavelength appropriate to produce a cytotoxic effect by the photosensitizer;
thereby treating the subject, for the disorder characterized by the presence of an unwanted organism.
In preferred embodiments, the unwanted organism, by way of example, can be: a microorganism, e.g., a bacterial cell, a fungal cell, a protozoan cell, a cell of Pneumocystis carinii; a virus; or, a parasitic helminth; or an arthropod.
In preferred embodiments where the unwanted organism is a bacterial cell, the bacterial cell can be a Staphylococcus, Streptococcus, Enterococcus, Mycobacterium, Pseudomonas, Salmonella, Shigella, Escherichia, Erwinia, Klebsiella, Borrelia, Treponema, Campylobacter, Helicobacter, Bordetella, Neisseria, Legionella, Leptospira, Serpulina, Mycoplasma, Bacteroides, Klebsiella, Yersinia, Chlamydia, Vibrio, Actinobacillus, Porphyria, Hemophilus, Pasteurella, Peptostreptococcus, Listeria, Propionibacterium, Mycobacterium, Corynebacterium or Dermatophilus cell. In more preferred embodiments the bacterial cell can be a Porphyromonas (Bacteroides) gingivalis; Bacteroides species including B. gingivalis (now known as Porphyromonas gingivalis), Eikenella corrodens, Fusobacterium nucleatum, Wolinella recta, Eubacterium species, Prevotella (Bacteroides) intermedia, Bacteroides forsythus, Capnocytophaga species, Actinobacillus actinomycetamcomitans, and Streptococcus mutans. 
In preferred embodiments where the bacterial cell is a Treponema cell, the disorder is trenchmouth, yaws, or pinta. In other embodiments the disorder is impetigo or cystic acne.
In preferred embodiments where the unwanted organism is a fungal cell, the cell can be a Candida or an Aspergillus cell. In preferred embodiments, the organism is Pneumocystis carinii. 
In preferred embodiments where the unwanted organism is a protozoan cell, the cell is an Entamoeba, a Toxoplasma, a Giardia, a Leishmania, a Crytosporidium, or a Schistosoma.
In preferred embodiments where the unwanted organism is a virus, the virus is an HIV, an HTLV, a hepatitis virus, an influenza virus, a rhinovirus, a papilloma virus, a measles virus, a Herpes virus, a rotavirus, a parvovirus, a psittacosis virus, or an Ebola virus.
In preferred embodiments where the target organism is an arthropod, the arthropod is a parasitic mite.
In preferred embodiments where the target organism is a helminth, the helminth is a nematode or a trematode. In preferred embodiments where the helminth is a nematode, the nematode is found in a subject with filariasis.
In preferred embodiments the target organism is an oral bacterial species, e.g., Porphyromonas (Bacteroides) gingivalis. 
In preferred embodiments, the conjugate does not include, e.g., it is not coupled, e.g., covalently or non-covalently coupled to: a PM; an antibody; an enzyme; a hormone; a receptor on a cell surface; or the ligand for a receptor on a cell surface.
In another aspect, the invention features, a method of treating a subject, for a disorder of the oral cavity characterized by the presence of an unwanted organism. The method includes:
administering to the subject, a conjugate which includes a photosensitizer coupled to a NPM targeting moiety, e.g., a conjugate described herein;
irradiating the subject with energy of a wavelength appropriate to produce a cytotaxic effect by the photosensitizer;
thereby treating the subject, for the disorder characterized by the presence of an unwanted organism.
In preferred embodiments the method includes topically administering the conjugate to an area of the subject which is infected with the unwanted organisms. The conjugate can be topically administered e.g., generally to the surfaces of the oral cavity, to the gums, to the periodontal tissue, to the periodontal pocket, to areas characterized by inflammation, to lesions, to fissures or imperfections in a tooth or gum, to dental carries, to cuts or incisions, e.g., those made in the course of dental or other medical care, or to wounds. In other embodiments the method includes systemic administration, e.g., by ingestion or injection. In other embodiments the method includes subcutaneous delivery, e.g., subcutaneous injection. In other embodiments the method includes local injection at or near the site of infection with the unwanted organism.
In preferred embodiments the radiation: is laser irradiation; or is delivered with a fiber optic devise.
In preferred embodiments the subject is suffering from: a disorder of the oral cavity which is characterized by the presence of an unwanted organism, e.g., a microbial organism, e.g., an unwanted bacterium, fungus, virus, or protozoan. The disorder can be one in which any of the teeth, gums, e.g., the periodontal tissue, tongue, tonsils, uvula, lining of the oral cavity, or parotid glands, are infected by the organism or otherwise affected by the disorder.
In preferred embodiments the disorder is an infectious oral disease.
In preferred embodiments the subject is suffering from: a periodontal disease, e.g., periodontitis or periodontosis; receding gums; acute ulcerative gingivitis; chronic gingivitis; periodontal abscess; early onset (juvenile) periodontitis; gingivitis of pregnancy; pericoronitis; infective stomatitis; cancrum oris; suppurative paratitis; acute or chronic osteomyelitis of the mandibles or maxilla; pulpitis or periapical infections.
In preferred embodiments the subject is suffering from an oral fungal infection, e.g., an actinomycosis, histoplasmosis, phycomycosis, aspergillosis, cryptococcosis, sporotrichosis, blastomycosis, or paracoccidioidomycosis infection.
In other preferred embodiments, the subject is suffering from an oral yeast infection, e.g., including a Candida infection of the oral cavity, e.g., candidosis (candidiasis), thrush, chronic candidosis and candidal (candididal) leukoplakia, or from a viral infection including primary herpetic stomatitis, or herpes labialis.
In preferred embodiments the subject, in addition to suffering from a disorder of the oral cavity, is suffering from an immune disorder, e.g., an acquired or inherited immune disorder. In particularly preferred embodiments the subject is suffering from AIDS or is HIV positive.
In preferred embodiments the unwanted organism is: an oral bacterial species, e.g., Porphyromonas (Bacteroides) gingivalis; Bacteroides species including B. gingivalis (now known as Porphyromonas gingivalis), Eikenella corrodens, Fusobacterium nucleatum, Wolinella recta, Eubacterium species, Prevotella (Bacteroides) intermedia, Bacteroides forsythus, Capnocytophaga species, Actinobacillus actinomycetamcomitans, and Streptococcus mutans. 
In preferred embodiments, the targeting moiety of the conjugate includes a salivary polypeptide, or an active fragment or analog thereof. Examples of salivary polypeptides are the histatins, e.g., histatin-1 through -8, or more preferably, histatin-1, -3, or -5. In preferred embodiments the targeting moiety includes histatin-5 residues 13-24, or corresponding residues from other histatins. In preferred embodiments the targeting moiety includes a histatin molecule which has been engineered to include an internal duplication.
In particularly preferred embodiments the targeting moiety includes a polylysine molecule.
In preferred embodiments the targeting moiety includes a polypeptide, e.g., a polyamino acid, which has been chemically modified to alter its charge, e.g., the charge of side chains of one or more amino acid residues of the polyamino acid. For example, one or more, or approximately 10, 25, 50, 75, 90 or 100% of the charged side chains can be modified. By modified is meant that a negative side chain, e.g., a glutamic acid, or an aspartic acid, side chain is made positive or neutral in charge, a positively charged side chain, e.g., the side chain of lysine, arginine, or ornithine is made negative or neutral in charge. By way of example, one or more of the side chains of polylysine can be made neutral or negative in charge.
In preferred embodiments, the conjugate does not include, e.g., it is not coupled, e.g., covalently or non-covalently coupled to: a PM; an antibody; an enzyme; a hormone; a receptor on a cell surface; or the ligand for a receptor on a cell surface.
In preferred embodiments: the photosensitizer produces singlet oxygen upon absorption of electromagnetic irradiation at the proper energy level and wavelength; the photosensitizer includes a porphyrin or porphyrin derivative; the photosensitizer includes chlorin e6 or a chlorin derivative.
In another aspect, the invention features a method of treating a subject for a periodontal disorder characterized by the presence of an unwanted organism. The method includes:
administering to the subject, a conjugate which includes a photosensitizer coupled to a NPM targeting moiety, e.g., a conjugate described herein;
irradiating periodontal tissue of the subject with energy of a wavelength appropriate to produce a cytotaxic effect by the photosensitizer;
thereby treating the subject, for the periodontal disorder.
In preferred embodiments the method includes topically administering the conjugate to an area of the subject which is infected with the unwanted organisms. The conjugate can be topically administered to the gums, to the periodontal tissue, to the periodontal pocket, to areas characterized by inflammation, or lesions. In other embodiments the method includes systemic administration, e.g., by ingestion or injection. In other embodiments the method includes subcutaneous delivery, e.g., subcutaneous injection. In other embodiments the method includes local injection at or near the site of infection with the unwanted organism.
In preferred embodiments the subject is suffering from: periodontitis or periodontosis; receding gums; acute ulcerative gingivitis; chronic gingivitis; periodontal abscess; early onset (Juvenile) periodontitis; gingivitis of pregnancy.
In preferred embodiments the subject, in addition to suffering from a periodontal disorder, is suffering from an immune disorder, e.g., an acquired or inherited immune disorder. In particularly preferred embodiments the subject is suffering from AIDS or is HIV positive.
In preferred embodiments the unwanted organism is: an oral bacterial species, e.g., Porphyromonas (Bacteroides) gingivalis; Bacteroides species including B. gingivalis (now known as Porphyromonas gingivalis), Eikenella corrodens, Fusobacterium nucleatum, Wolinella recta, Eubacterium species, Prevotella (Bacteroides) intermedia, Bacteroides forsythus, Capnocytophaga species, Actinobacillus actinomycetamcomitans, and Streptococcus mutans. 
In preferred embodiments, the targeting moiety of the conjugate includes a salivary polypeptide, or an active fragment or analog thereof. Examples of salivary polypeptides are the histatins, e.g., histatin-1 through -8, or more preferably, histatin-1, -3, or -5. In preferred embodiments the targeting moiety includes histatin-5 residues 13-24, or corresponding residues from other histatins. In preferred embodiments the targeting moiety includes a histatin molecule which has been engineered to include an internal duplication.
In particularly preferred embodiments the targeting moiety includes a polylysine molecule.
In preferred embodiments the targeting moiety includes a polypeptide, e.g., a polyamino acid, which has been chemically modified to alter its charge, e.g., the charge of side chains of one or more amino acid residues of the polyamino acid. For example, one or more, or approximately 10, 25, 50, 75, 90 or 100% of the charged side chains can be modified. By modified is meant that a negative side chain, e.g., a glutamic acid, or an aspartic acid, side chain is made positive or neutral in charge, a positively charged side chain, e.g., the side chain of lysine, arginine, or ornithine is made negative or neutral in charge. By way of example, one or more of the side chains of polylysine can be made neutral or negative in charge.
In preferred embodiments, the conjugate does not include, e.g., it is not coupled, e.g., covalently or non-covalently coupled to: a PM; an antibody; an enzyme; a hormone; a receptor on a cell surface; or the ligand for a receptor on a cell surface.
In preferred embodiments: the photosensitizer produces singlet oxygen upon absorption of electromagnetic irradiation at the proper energy level and wavelength; the photosensitizer includes a porphyrin or porphyrin derivative; the photosensitizer includes chlorin e6 or a chlorin derivative.
In another aspect, the invention features, a method of treating a subject having an acquired immune disorder having an acquired immune disorder, for a disorder of the oral cavity characterized by the presence of an unwanted organism. In preferred embodiments the unwanted organism is other than an organism which is causative of the acquired immune disorder. The acquired immune disorder can be, e.g., AIDS, or an HIV infection. The method includes:
administering to the subject, a conjugate which includes a photosensitizer coupled to a NPM targeting moiety, e.g., a conjugate described herein;
irradiating the subject with energy of a wavelength appropriate to produce a cytotaxic effect by the photosensitizer;
thereby treating the subject, for the disorder characterized by the presence of an unwanted organism.
In preferred embodiments the method includes topically administering the conjugate to an area of the subject which is infected with the unwanted organisms. The conjugate can be topically administered e.g., generally to the surfaces of the oral cavity, to the gums, to the periodontal tissue, to the periodontal pocket, to areas characterized by inflammation, to lesions, to fissures or imperfections in a tooth or gum, to dental carries, to cuts or incisions, e.g., those made in the course of dental or other medical care, or to wounds. In other embodiments the method includes systemic administration, e.g., by ingestion or injection. In other embodiments the method includes subcutaneous delivery, e.g., subcutaneous injection. In other embodiments the method includes local injection at or near the site of infection with the unwanted organism.
In preferred embodiments the radiation: is laser irradiation; or is delivered with a fiber optic devise.
In preferred embodiments the unwanted organism is, e.g., a microbial organism, e.g., an unwanted bacterium, fungus, virus, or protozoan. The disorder can be one in which any of the teeth, gums, e.g., the periodontal tissue, tongue, tonsils, uvula, lining of the oral cavity, parotid glands, are infected by the organism or otherwise affected by the disorder.
In preferred embodiments the disorder is an infectious oral disease.
In preferred embodiments the subject is suffering from: a periodontal disease, e.g., periodontitis or periodontosis; receding gums; acute ulcerative gingivitis; chronic gingivitis; periodontal abscess; early onset juvenile) periodontitis; gingivitis of pregnancy; periocoronities; infective stomatitis; cancrum oris; suppurative paratitis; acute or chronic osteomyelitis of the mandibles or maxilla; pulpitis or perioapical infections.
In preferred embodiments the subject is suffering from an oral fungal infection, e.g., an actinomycosis, histoplasmosis, phycomycosis, aspergillosis, cryptococcosis, sporotrichosis, blastombycosis, or paracoccidioidomycosis infection. In other preferred embodiments, the subject is suffering from an oral yeast infection, e.g., including a Candida infection of the oral cavity, e.g., candidosis (candidiasis), thrush, chronic candidosis and candidal (candididal) leukoplakia, or from a viral infection including primary herpetic stomatitis, or herpes labialis.
In preferred embodiments the unwanted organism is: an oral bacterial species, e.g., Porphyromonas (Bacteroides) gingivalis; Bacteroides species including B. gingivalis (now known as Porphyromonas gingivalis), Eikenella corrodens, Fusobacterium nucleatum, Wolinella recta, Eubacterium species, Prevotella (Bacteroides) intermedia, Bacteroides forsythus, Capnocytophaga species, Actinobacillus actinomycetamcomitans, and Streptococcus mutans. 
In preferred embodiments, the targeting moiety of the conjugate includes a salivary polypeptide, or an active fragment or analog thereof. Examples of salivary polypeptides are the histatins, e.g., histatin-1 through -8, or more preferably, histatin-1, -3, or -5. In preferred embodiments the targeting moiety includes histatin-5 residues 13-24, or corresponding residues from other histatins. In preferred embodiments the targeting moiety includes a histatin molecule which has been engineered to include an internal duplication.
In particularly preferred embodiments the targeting moiety includes a polylysine molecule.
In preferred embodiments the targeting moiety includes a polypeptide, e.g., a polyamino acid, which has been chemically modified to alter its charge, e.g., the charge of side chains of one or more amino acid residues of the polyamino acid. For example, one or more, or approximately 10, 25, 50, 75, 90 or 100% of the charged side chains can be modified. By modified is meant that a negative side chain, e.g., a glutamic acid, or an aspartic acid, side chain is made positive or neutral in charge, a positively charged side chain, e.g., the side chain of lysine, arginine, or ornithine is made negative or neutral in charge. By way of example, one or more of the side chains of polylysine can be made neutral or negative in charge.
In preferred embodiments, the conjugate does not include, e.g., it is not coupled, e.g., covalently or non-covalently coupled to: a PM; an antibody; an enzyme; a hormone; a receptor on a cell surface; or the ligand for a receptor on a cell surface.
In preferred embodiments: the photosensitizer produces singlet oxygen upon absorption of electromagnetic irradiation at the proper energy level and wavelength; the photosensitizer includes a porphyrin or porphyrin derivative; the photosensitizer includes chlorin e6 or a chlorin derivative.
In another embodiment, the invention includes a method for making conjugate molecules, the method comprising:
supplying a backbone, e.g., a polypeptide backbone;
coupling, e.g., covalently coupling, a photosensitizer to the backbone;
coupling, e.g., covalently coupling, a targeting moiety, e.g., a targeting moiety described herein, to the backbone.
In preferred embodiments, the coupling reactions involve an activated ester moiety of a photosensitizer. In more preferred embodiments, an amino group on the backbone reacts as a nucleophile, displacing the leaving group from the photosensitizer active ester. In preferred embodiments, the targeting moiety is coupled to the backbone with a coupling agent.
In preferred embodiments, the conjugate does not include, e.g., it is not coupled, e.g., covalently or non-covalently coupled to: a PM; an antibody; an enzyme; a hormone; a receptor on a cell surface; or the ligand for a receptor on a cell surface.
In another aspect, the invention features, a kit for elimination of an unwanted organism. The kit includes a photosensitizer coupled to a targeting moiety and instructions for use.
In preferred embodiments, the conjugate does not include, e.g., it is not coupled, e.g., covalently or non-covalently coupled to: a PM; an antibody; an enzyme; a hormone; a receptor on a cell surface; or the ligand for a receptor on a cell surface.
Photodynamic therapy involves the use of a light activatable compound, or photosensitizer, together with light of the correct wavelength, to produce a cytotoxic effect. In order to increase the specificity of the photosensitizer for its target, the photosensitizer may be bound to a targeting moiety. Methods and conjugates of the invention features the use of NPM-targeted photosensitizers. NPM""s can deliver photosensitizer to a target in an efficient and cost effective manner. Compositions of the invention are advantageous in that (i) they do not need to be internalized to kill bacteria, since illumination generates toxic oxygen species which can diffuse through the bacterial cell wall, (ii) the generation of toxic oxygen species can have a local effect in stimulating the host immune response which can assist in eradicating bacteria and in promoting healing of the wound, (iii) they produce a cytotoxic response only in the area subject to illumination.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those herein can be used in the practice or testing of the present invention, the preferred methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.